1. Field of Invention
This invention relates to the field of data processing of measurements and more specifically to a topographical measurement system.
2. Description of Related Art
Each year federal and state governments conduct thousands of environmental, hydrological and meteorological research studies which require highly accurate data about soil elevation changes. Soil elevation data sets must be gathered on site (in situ) at critical locations over timed intervals. The international scientific community relies on accurate soil elevation data sets to predict and model changes in sea level, climatological events, marsh erosion and the health of estuary ecosystems. Despite the clear scientific need and economic value of building repositories of highly accurate soil elevation data sets over time, there is limited technology for doing so.
The Rod Surface Elevation Table (RSET) tool is the technology currently used for in situ procurement of soil elevation data in 25 countries and 25 US states. The RSET allows scientists to obtain multiple contemporaneous soil elevation measurements along a defined linear path at a research site. Using the RSET, researchers vertically place rods or pins along the linear path by sliding them through apertures in a linear guide called a “measuring arm.” One end of each rod or pin contacts the soil surface. The portion of each rod or pin that remains above the aperture on the measuring arm will then vary over time due to changes in soil elevation.
The measuring arm is attached to a stationary object called a “benchmark.” The benchmark maintains the position of the measuring arm at a constant elevation, irrespective of any changes in the surface elevation. Each rod or pin represents a measurement point. To obtain measurements for each point, a researcher manually measures the portion of the respective rod or pin which remains above the measuring arm.
Despite widespread reliance on the RSET by the scientific community, there are two inherent types of errors associated with measurements obtained using the RSET. These errors, alone and in combination, materially compromise the accuracy of data obtained using the RSET. As a result, researchers typically assume a maximum precision of about 0.5 cm due to variations resulting from manual placement and measurement.
Introduction of a first type of error occurs during manual placement of the rods or pins. An operator may inadvertently push rods or pins below the soil surface. As a result, soil elevation measurements can vary based on the amount of pressure or force applied by a particular individual. Researchers cannot adjust soil elevation data sets based on how deeply particular operators may have embedded the rods or pins in the soil surface.
The second type of error is typically introduced when taking measurements after placement of the rods or pins. An operator must accurately measure a distance on the rod or pin to extrapolate soil elevation for each sample point. Errors result when operators utilize different measuring tools or when a single operator is not consistent in measuring and recording. One operator may not be able to duplicate another operator's method of making measurements, resulting in inconsistent data if an original operator is replaced.
Additionally, the RSET yields only limited amounts of data for a given point in time. Scientific research is often restricted or delayed by the slow rate of data acquisition. Studies can be delayed for two or more years due to waits for RSET data.
There is an unmet need for an in situ soil elevation data gathering tool that can produce a large number of soil elevation data sets over a shorter period of time.
There is a further unmet need for an in situ soil elevation data gathering tool that can reliably produce highly accurate and precise soil elevation data sets.
There is a further unmet need for an in situ soil elevation data gathering tool that can collect large scale soil elevation data sets currently unavailable to researchers due to limitations of the RSET tool.